Steering mechanism



July 13, 1937. A; Q, MC LL M 2,086,814

STEERING MECHANI SM Filed June 20, 1934 4 Sheets-Sheet I INVENTORhvoefig Q/VcCaaum ATTORNEY July 13, 1937. A. O. MCCQLLUM 2,086,814

STEERING MECHANISM Filed June 20, 1954 4 Sheets-Sheet 5 IN VEN TOR.

62 @A/DEfWQ/VCCOLLV/V Wan BY F 9 ATTORNEY Patented July 13, 1937 TEDSTEERING MECHANISM Application June 20, 1934, Serial No. 731,510

6 Claims.

This invention relates to steering mechanism, and more particularly tofluid pressure steering mechanism. I

An object of the invention is to provide an emcient and simplified fluidpressure operated steering mechanism for motor vehicles.

Another object of the invention is to provide a fluid pressure operatedsteering mechanism in which a maximum amount of movement may be given tothe steering traction Wheels of a vehicle .by a minimum amount ofmovement of. the'steering wheel.

Another object of the invention is to provide a fluid pressure operatedsteering mechanism for a motor vehicle including means for synchronizinga fluid compression means with a fluid pressure actuated means.

A further object of the invention is to provide a fluid pressureoperated steering mechanism for motor vehicles having meansautomatically operable to compensate for expansion or contraction of thefluid in the system due to changes in atmospheric conditions.

Other objects of the invention will appear from the followingdescription taken in connection with the drawings which form apart ofthis specification, and in which:--

Figure 1 is a top plan view of a motor v hicle partly broken awayillustrating the inve on as installed;

Figure 2 is a longitudinal sectional v ew of a fluid compressionmechanism;

Figure 3 is a sectional view substantially on line 3--3, Figure 2;

Figure 4 is a side elevation of of the fluid compression mechanism;

Figure 5 is a cross-sectional view of the fluid compression mechanismsubstantially on line ti-e5, Fig. 2;

Figure 6 is an enlarged sectional stantially on line 6-B, Figure 3;

Figure '7 is an enlarged sectional view substantially on line 1-1,Figure 6;

Figure 8 is a detail view of a valve mechanism;

Figure 9 is a longitudinal sectional view of the fluid pressure actuatedmechanism;

Figure 10 is a side elevation of the fluidactuated mechanism partlyinsection, the section being substantially on line I0I l, Figure 9; and

Figure 11 is a cross-sectional view substantially on line II-I I, Figure9.

Referring to the drawings details of the invention, I 0 represents amotor vehicle chassis frame including side members I2 connected bycross-members I4. The frame is supported by an axle I6 having steeringknuckles I8 pivoted to the respective ends of the axle, and wheels 28are rotatably mounted on the steering knuckles. The frame supports aprime mover 22, and a body 24'including a dash 26.

abuts the web 38.

view sub- 1 for more specific in one end of the casting are posed guides42 and 44.

50 and 52, and inlet ports 54 and 56.

Corresponding reciprocal pistons 58 and 60 in the cylinders 34 and 36are each provided with spaced circumferential ted leak-proof cups 62,andthat portion of the piston between the; cups 82 is reduced incrosssection to provide an annular chamber 64. Each piston is cut awayas at 86, and seated in a notch 68 in the cut-away portion is acase-hardened block 10 adapted to slide freely on the guides t2 and 34,and the blocks have opposed threaded faces 12 the object of which willhereinafter appear.

' gain The cylinders have 1 heads 46 and 48' provided withdischarge-ports 1o grooves in which are fit= A steering column 14supported in a steering I post I6 on the dash 26 has secured thereto aconventional steering wheel 18. The steering column encloses thethrottle control rod All and The column has formed thereon right andleft threads 88 receiving the threads 12 on the blocks I8, and a collar82 on the column supports one race of a thrust bearing 84, the otherrace of which is supported in a sleeve 86 formed on' a head 88 bolted orotherwise secured to the casting.

A valve 90 on the wall of the cylinders 34- and 36 includes parallelcylinders 92 and 94 having their respective ends closed as by heads 96.The latter cylinders are divided by diaphragms 98 and I80 intocompartments I02, I04, I06'and I88, and the diaphragms have concentricopenings. The compartments I02 and I06 are connected by a passage ill],and the compartments I04 and I08 are connected by a passage II2. I Thecompartments I02 and i116 each has a port H4 and H6 communicating withthe cylinder 34, and the compartments IM and I08 each has a port H8 andI28 communicating with the cylinder 36. The cylinders 92 and 94 aresupplied with fluid from a reservoir I22, and the reservoir has thereina spring-pressed piston I24 for placing the, fluid under pressure. Thereservoir isconnected to the cylinders 92 and 94 by a passage I28 andI28 respectively.

The cylinders 92 and 84 have therein corresponding spring-pressedpistons I and I32 arranged in an oppositely disposed relation withrespect to one another. The piston I 30 in the cylinder 92 has a reducedbody portion providing an annular chamber I34 and a concentric extensionitt reciprocable in the opening in the diaphragm 88 and the compartmentNM. The ex tended portion has an axial passage I38 communicating with adiametral passage I40 through .the body of the piston. A leak-proof cupI42 is seated on the diaphragm 98 within the compartment I04, and aflange on the inner perimeter of the cup extends beyond the end of theextension but is arranged in the oppositely disposed position. Thispiston has a reduced body portion providing an annular chamber I54 and aconcentric extension I56 reciprocable in the opening'in the diaphragmI00 and the compartment I06. The extension I56 has an axial passage I58communicating with'a diametral passage I60 through the body of thepiston. A leak-proof cup I62 is seated on the diaphragm I00 within thecompartment I06. Thiscup has a flange on its inner perimeter extendingbeyond the concentric extension I56 when the piston is in retractedposi:

tion.- The cup provides in cooperation with a plug I64 fitted in theopen end of thepassage I58 a valve for control of ports I66 providingcommunications betweenthe chamber I06 and the passage I58 for the flowof fluid fr'om chamber I06 through the passages I58 and I60 to thechamber I54, and thence to the reservoir. The head of the piston has aplurality of openings I68 controlled by a collapsible leak-proof cup I10seated on the head, and a spring I12 sleeved on the piston between-itshead and the diaphragm I00 urges the piston to its seat.

A cylinder I14 bolted or otherwise secured to the forward cross-memberof the chassis frame hasheads I16 and I18 threaded in itsrespectiveends. A double-end reciprocal piston I80 in the cylinder divides thecylinder into two chambers I82 and I84. The pisto'n has on itsrespective heads leak-proof cups I86 and I88 held against displacementby-springs I90 and I92 interposed between the cups and the respectiveheads. The

- head I16 has a port connected by a conduit I64 to a port in the head48 of the cylinder 36, and

the head I18 has a port connected by a conduit I96 to a port in the head46 of the cylinder 34.

. The chamber I82 of the cylinder. I14 has a port I08 communicating witha. valve chamber 200 having therein a check valve 202 controlling theport, and the chamber is connected as by a fitting 204 and a conduit 206to the port 54 in the cylinder 34. The other chamber I84 of the cylinderI14 has a port 208 communicating with a. chamgear 220 formed on a shaft222 suitably journaled in a housing 224 formed integral with thecylinder I14, and keyed to the shaft is an arm 226 connected by adrag-link 228 to a steering arm 230. The steering arm 230 is connectedby a rod 232 to another steering arm 234, the steering arms being formedintegral with the steering knuckles I8.

In the operation of a motor vehicle equipped with this fluid pressuresteering mechanism, the operator steers the'vehicle in-the conventionalmanner. Should the operator desire to make a right-hand turn, thesteering wheel 18 is turned to the right. This movement of the steeringwheel is transmitted through the steering column 14 and threads thereonto the blocks 10 to move the blocks in reverse direction, and thismovement of the blocks 10 is transmitted to the pistons 58 and 60 tomove the piston 60 on its compression stroke and to move 'the piston 58on its retraction stroke.

As the piston 60 moves on its compression stroke, the fluid in thecylinder 36 is displaced through the conduit I94 to the chamber I82 ofthe cylinder I14, resulting in moving piston I80 to the right. Thismovement of the piston I80 is transmitted through the rack 2 I8 andpinion 220 to the shaft 222-resulting in rotation of the shaft andturning the arm 226 attached thereto to the left. This movement of thearm 226 is' transmitted throughthe conventional drag-link 228 andsteering rod 232 to the steering arms 230 and 234 to shift these'arms tothe left, resulting in turning the wheels to the right.

During this movement the fluid in chamber I84 is displaced therefromthrough the conduit I 96 to the cylinder 34. Due to pressure in thechamber I82 the check valve 202 is retained in open position. Thetripping of this valve 202 establishes communication between the chamberI82 and the cylinder 34 by way of the conduit 206 and the port 54. Thefluid enters the cylinder 34 in the chamber 64 between the cups 62 onthe piston'58, where the flow of the fluid is arrested due to closing ofthe port II6 by movement of the piston .58.

During the compression stroke of the piston 60 to displace the fluidfrom the cylinder 36 the fluid passes through the port II8 into chamberI04, thence through passage II2 into chamber I08,

and introduces pressure in the chamber I08 causchamber I02, passage IIO,chamber I06, port I66, passages I 58 and I60, through the piston, thechamber I54, and passage I28 to the reservoir.

Now, upon turning the steering wheel to the left to steer the vehiclestraight ahead, the pis-' tons 58 and 60 are again shifted in oppositedire'ctions. The piston 60 is retracted and the piston 58 is advanced tomove the pistons to normal position. At the initial period of thismovement pressure in the cylinder 36 is released, resulting in releaseof pressure in the chamber I08 and consequent movement of the piston I32under the influence of spring I12 to close the-port I66 and shutting offcommunication between the cylinder 34 and the reservoir. Simultaneouslywith this movement, fluid in the cylinder 34 is displaced through theport 'I I4 to the chamber I02, introducing pressure in this chamber,causing .r'novement of the piston I30 to open the valve I46 -mittedthrough the rack m, pinion m, shaft 222, arm 226, drag-link 228 andsteering rod 232 to the steering arms 230 and 234, to turn the wheels tostraight-forward position. As the piston I80 is returned to neutralposition, fluid in the chamber I82 is displaced through the conduit I94to the cylinder 36.

When the piston I80 returns to neutral position, should the pistons 58and 60 remain out of neutral, they are automatically returned to neutralposition upon subsequent operation as, for example,-suppose the piston58 is advanced and the piston 60 is retracted,--upon advancement of thepiston 60 by slight movement of the steering wheel, fluid is displacedfrom the cylinder 36 through the conduit I94 into the chamber I82 of thecylinder I14, thence through port I98, past valve 202, through conduit206 and port 54, to the cylinder 34 into chamber 64 between the cups 62on the piston 58, thence through port I I6 into the chamber I06, thencethrough passage IIO to chamber I02, and from this chamber through portII4 to the cylinder 34 forward of the head of the piston 58 to fill thatportion of the cylinder 34 forward of the head of the piston. When thepistons 53 and 60 assume neutral position communication between thechambers 34 and 36 and the ports H6 and I20 is established.

Due to expansion of fluid caused by atmos-- pheric conditions, pistonsI30 and I32 are automatically actuated to trip the valves I46 and I66 soas to establish communication between the system and the reservoir.Should the fluid in the system contract due to a, drop in temperature,fluid wi1l be drawn from the reservoir through the openings I48 and I68in the heads of the pistons I30 and I32, past the collapsible leakpro'ofcups I50 and I10 thereoninto the system.

Altlough this invention has been described in connection with certainspecific embodiments, the principles involved are susceptible ofnumerous other applicationsthat will readily occur to persons skilled inv the art. The invention is, therefore, to be limited only as indicatedby the scope of the appended claims.

Having thus described the various features of the invention, what Iclaim is new and desire to secure by Letters Patent is:

1. "A hydraulic steering system comprising an actuating device includinga pair of pistons movable concomitantly in opposite directions, anactuated-device including a double-actingpiston,

fluid pressure delivery means coupling the devices, means fortransferring fluid from the high pressure end of the double-actingpiston to the piston of the actuating device moving on its retractionstroke effective upon movement of the double-acting piston pastneutral-position on its compression stroke.

2. A hydraulic steering system comprising an actuating device includinga pair of pistons movable concomitantly in opposite directions, meansvehicle comprising an actuating device including a pair of cylindershaving pistons reciprocable therein, means for actuating the pistonsconcomitantly to move one on its compression stroke and the other on itsretraction stroke, an actuated device including opposed cylinders and adoubleacting piston reciprocable therein, means connecting thedouble-acting piston to the steering arm of the vehicle, fluid deliverypipes connecting the respective cylinders of the actuating device to thecorresponding cylinders of the actuated device, means for synchronizingthe actuating device with the actuated device including fluid returnpipes connecting the cylinders of the actuated device to the cylindersof the actuating device, and valves for controlling the flo'w of fluidfrom the actuated device to the actuating device operated' by pressurecreated in the system by the movement of the pistons of the actuatingdevice.

4. A hydraulic steering system comprising an actuating device includinga pair of pistons, means for actuating the pistons concomitantly to moveone on its compression stroke and the other on its retraction stroke, anactuated device including a double-acting piston, means connecting thedouble-acting piston to 5 steering arm, fluid pressure delivery meanscoupling the devices, means for synchronizing the actuating device withthe actuated device including means effective upon movement of thedouble-acting piston past neutral position'for transferring fluid i fromthe high pressure side of the double-acting piston to the head of thepiston in the actuating device moving on its retraction stroke.

5. A hydraulic steering system comprising an actuating device includinga pair of cylinders, a reservoir for supplying fluid to the cylinders,pistons ineach of the cylinders; means for slmul-, taneously actuatingthe pistons to move one on itscompression stroke and the other on itsretraction stroke, an actuated device including a cylinder, a doubleacting piston therein, fluid pressure delivery means coupling therespective cylinders of the actuating device to the cylinder of theactuated device, means for synchronizing the actuating device with theactuated device including means effective upon movement of thedouble-acting piston past neutral position for transferring fluid fromthe high pressure side of the double-acting piston to the head of thepiston in the actuating device moving on its retraction stroke. 7

6. A hydraulic steering system comprising an actuating device includinga pair of cylinders, a reservoir for supplying fluid to the cylinders, apiston in each of the cylinders, means for simultaneously actuating thepistons to move one on its compression stroke and the other on itsretraction stroke, an actuating device including. a cylinder, adouble-acting piston therein, fluid pressure delivery means coupling therespective cyllnders of the actuating device with the respective ends ofthe cylinder of the actuated device, means for synchronizing theactuating device with the actuated device including means effective uponmovement of the double-acting piston past neutral position fortransferring fluid from the high pressure side of the double-actingpiston to the head of the piston in the actuating device moving on itsretraction stroke, and valve mechanism controlling the flow of fluidfrom the reservoir to the cylinders ofthe actuating device operable byfluid under pressure in one of the cylinders of the actuating device toestablish communication between the reservoir and the other cylinder ofthe actuating device. I

ANDREW 0. MCCOLLUM.

